[fcstory]

So my father in law has a compressor in his shop that is on a double pole 30 (10/3) system with a massive disconnect. He invariably wants to be able to put it on a 3 way system. Weird, I know. It gets even weirder.. He wants to be able to cut it off with 2 switches on a 3 way system. One in his house, and the other next to the compressor. However, He wants the disconnects to be ran with 14/3.. I told him it can never work because the switches have to handle the same draw as the compressor.. Now we are talking about household switches so it doesn't look out of place in his hall way.

Am I wrong?

And at the very least.. I'm sure this compressor would be fine on a double pole 20 with 12/3.. I'll have to check the draw, But if thats the case.. Then I could always run a 12/3 to a 2 pole disconnect, but im still lost with how I'd run a 2 pole disconnect on a 3 way system..

 

[Speedy Petey]

Use a relay or contactor with a 120V coil.

 

[MTW]

I b t l

 

[pudge565]

Why the hell is it wired with 10-3? If its 240 10-2 would have been fine. I've never seen a 240/120 compressor.

 

[ponyboy]

Why do you think the switched need to carry the load please

 

[RIVETER]

So my father in law has a compressor in his shop that is on a double pole 30 (10/3) system with a massive disconnect. He invariably wants to be able to put it on a 3 way system. Weird, I know. It gets even weirder.. He wants to be able to cut it off with 2 switches on a 3 way system. One in his house, and the other next to the compressor. However, He wants the disconnects to be ran with 14/3.. I told him it can never work because the switches have to handle the same draw as the compressor.. Now we are talking about household switches so it doesn't look out of place in his hall way.

Am I wrong?

And at the very least.. I'm sure this compressor would be fine on a double pole 20 with 12/3.. I'll have to check the draw, But if thats the case.. Then I could always run a 12/3 to a 2 pole disconnect, but im still lost with how I'd run a 2 pole disconnect on a 3 way system..

I believe to wire it that way would be unsafe. "Within" sight...etc.

 

[dspiffy]

I was going to say a relay, and someone else beat me to it. I wouldnt want to run the supply to the compressor all the way to the house and back, 14 or not.

Depending on how far the house is, you could even use X10 . . . you'd still have to use a relay, I dont believe they make X10 modules with high enough ratings.

 

[wendon]

So my father in law has a compressor in his shop that is on a double pole 30 (10/3) system with a massive disconnect. He invariably wants to be able to put it on a 3 way system. Weird, I know. It gets even weirder.. He wants to be able to cut it off with 2 switches on a 3 way system. One in his house, and the other next to the compressor. However, He wants the disconnects to be ran with 14/3.. I told him it can never work because the switches have to handle the same draw as the compressor.. Now we are talking about household switches so it doesn't look out of place in his hall way.

Am I wrong?

And at the very least.. I'm sure this compressor would be fine on a double pole 20 with 12/3.. I'll have to check the draw, But if thats the case.. Then I could always run a 12/3 to a 2 pole disconnect, but im still lost with how I'd run a 2 pole disconnect on a 3 way system..

Does the compressor have a starter or is the pressure switch handling the full load current??

 

[EBFD6]

Why do you think the switched need to carry the load please

???

Because it's a disconnect. Disconnects typically (always) will see the full load of the equipment they are feeding.

Maybe I'm misunderstanding your question, but this is pretty basic.



I agree with others. The only way to do what he wants would be a relay or contactor.

 

[EBFD6]

I believe to wire it that way would be unsafe. "Within" sight...etc.

He could control a contactor with the 3-way setup. He would still need a separate lockable disconnect for the compressor feed within sight of the equipment IMO.

 

[ponyboy]

??? Because it's a disconnect. Disconnects typically (always) will see the full load of the equipment they are feeding. Maybe I'm misunderstanding your question, but this is pretty basic. I agree with others. The only way to do what he wants would be a relay or contactor.

I was implying the switch would be carrying a control circuit. I think this is the way most guys would do it

 

[Southeast Power]

So my father in law has a compressor in his shop that is on a double pole 30 (10/3) system with a massive disconnect. He invariably wants to be able to put it on a 3 way system. Weird, I know. It gets even weirder.. He wants to be able to cut it off with 2 switches on a 3 way system. One in his house, and the other next to the compressor. However, He wants the disconnects to be ran with 14/3.. I told him it can never work because the switches have to handle the same draw as the compressor.. Now we are talking about household switches so it doesn't look out of place in his hall way.

Am I wrong?

And at the very least.. I'm sure this compressor would be fine on a double pole 20 with 12/3.. I'll have to check the draw, But if thats the case.. Then I could always run a 12/3 to a 2 pole disconnect, but im still lost with how I'd run a 2 pole disconnect on a 3 way system..

I can only offer one word on this subject:
Pressure switch.

 

[Mshea]

The 3 way idea will not meet OSHA requirments for a disconnect and neither will a relay. he can work a control scheme that works from the house and the shop but there better be a disconnecting means by the machine after this control idea

 

[EBFD6]

The 3 way idea will not meet OSHA requirments for a disconnect and neither will a relay. he can work a control scheme that works from the house and the shop but there better be a disconnecting means by the machine after this control idea

Osha is for workplaces, doesn't apply to a residence.

 

[BBQ]

The 3 way idea will not meet OSHA requirments for a disconnect and neither will a relay.

Even if OSHA did apply the installation would be allowed as the controller.

You would still need a disconnecting means within sight of the motor.

 

[jza]

This thread is full of fail.

 

[B4T]

Why not just use the pressure switch as the control instead of adding another relay to the mix.. :blink::blink:

Terminal 1&3 is what you need for 2-wire control...

 

[BBQ]

Why not just use the pressure switch as the control instead of adding another relay to the mix.. :blink::blink:

Terminal 1&3 is what you need for 2-wire control...

So you are suggesting running a 30 amp circuit through 14 AWG and a pair of three ways?

Not a good plan.

 

[B4T]

So you are suggesting running a 30 amp circuit through 14 AWG and a pair of three ways?

Not a good plan.

The pressure switch doesn't have 30 amps going through it.. :blink::blink:

Terminal 1&3 goes to the coil on the motor starter... but you know that.. :blink::blink:

 

[wendon]

The pressure switch doesn't have 30 amps going through it.. :blink::blink:

Terminal 1&3 goes to the coil on the motor starter... but you know that.. :blink::blink:

Except the OP never said it had a motor starter. Possible only has a pressure switch heavy enough to handle the motor current. In fact the OP hasn't
said a whole lot since the 1st post. Reading between the lines, I question if he's actually an electrician!!!:no::no: